Cylindrical-parabolic reflector with printed antenna structures

The paper presents concept of design and realization of the new class of printed antenna structures which consist of a linear axial array of dipoles, subreflector, feed network and a bal-un, all printed on a common dielectric substrate. The array is positioned on the axis focus of the cylindrical-parabolic reflector. Use of the reflector enables reducing back side radiation and shaping beamwidth in H-plane thus obtaining higher gain while the printed subreflector gives the possibility of achieving additional gain. Besides, by using dipoles with pentagonal shape that operate on the second resonance, enhanced bandwidth of the array has been accomplished. Four variants of such arrays have been realized: two of them with 8 radiating elements for the frequency range around 26 GHz - one with uniform and the other with tapered feed distribution, featuring gains of 27.5 dBi and 25.7 dBi, respectively. The latter has the side lobe suppression of 28 dB in E-plane. Two other arrays that are intended for ranges around 23 GHz and 60 GHz have 16 radiating elements, uniform feed distribution and measured gains of 33 dBi and 34 dBi, respectively. Bandwidths of all realized model for S11 less than -10 dB is around 30 %. In all cases agreement between simulated and measured results is very good